void main(List<String> args) {
  Man man = new Man('Jack', 20);
  man.drive();

  Women women = new Women('Rose', 18);
  women.dreesUp();
}

class Person {
  String? name;
  int? age;

  Person(String name, int age) {
    this.name = name;
    this.age = age;
  }

  say() {
    print('$name今年$age');
  }
}

class Man extends Person {
  Man(super.name, super.age);

  drive() {
    print('开车');
  }
}

class Women extends Person {
  Women(super.name, super.age);

  dreesUp() {
    print('打扮');
  }
}
